MID-WEST Instrument – Diaphragm Type Differential Pressure Gauges

Diaphragm type: ± 2% or ± 5% Full Scale Accuracy. The high and low-pressure ports are completely isolated from each other. There is no bypass and therefore they are ideally suited for use on dissimilar fluids, air, gases, or liquids with a high concentration of solids, etc. They also come in a variety of sizes allowing for very sensitive measurements. The Differential Pressure is sensed by the movement of an elastomer diaphragm against a precision calibrated range spring. The change in position of the diaphragm in response to the change in Differential Pressure moves an internal magnet. This magnet, in turn, causes a rotary magnet external to the gauge body to rotate. This rotary magnet has a pointer attached which indicates the differential pressure on the
dial.
Diaphragm-Type Differential Pressure Gauges are available with one or two hermetically sealed reed switches or 4-20mA transmitter depending on model. The switches are adjustable within a defined percentage of the full scale range of the gauge and are available in SPDT and SPST, normally open or normally closed configurations for various load/power ratings. The switches can be set to activate or deactivate on rising or falling pressure. Switches are “CE” marked per the EU low voltage directive. Mid-West Diaphragm-type Differential Pressure Gauges can be configured for use in hazardous locations. All Hazardous Location Switches are both CSA and UL listed. The CSA & UL listings are for the entire assembly and not just the enclosure. IECEx certified switches are available now on model 240.

Models 130, 140, 142, 522, 700

Product Features:

  • Wide Selection of DP Ranges & Scales
  • Elastomer Diaphragm Sensing Element, No Cross Port Leakage
  • Up to 500 PSIG Working Pressure (34 bar)
  • Over-Range Protection, High over Low and Low over High
  • Gauge Housings available in Aluminum, Brass, 316/316L Stainless Steel and Polysulfone Thermoplastic
  • Wide Range of elastomers

Special Features:

  • Over-range Protection – Full to Maximum Working Pressure
  • Panel Mounting – Standard
  • Pipe Mounting Kit – Optional – 2″ U-Bolt
  • Wall Mounting – Optional – Rear Mount
  • NACE Compliance – Optional

Product Features:

  • DP Ranges from 0-25 PSID to 0-100 PSID
  • Elastomer Diaphragm Sensing Element,
    No Cross Port Leakage
  • Up to 3000 PSIG Working Pressure (200 bar)
  • Over-Range Protection,
    High over Low and Low over High
  • Gauge Housings available in Aluminum, Brass, 316/316L Stainless Steel and Acetal Plastic
  • Wide Range of Elastomers

Special Features:

  • Over-range Protection Full to Maximum Working Pressure
  • Panel Mounting Standard, Front or Rear Panel
  • Pipe Mounting Kit Optional – 2″ U-Bolt
  • Wall Mounting Optional – Rear Mount
  • NACE Compliance Optional

Product Features:

  • DP Ranges from 0-20” WC to 0-25 PSID
  • Elastomer Diaphragm Sensing Element, No Cross Port Leakage
  • Up to 3000 PSIG Working Pressure (200 bar)
  • Over-Range Protection, High over Low and Low over High
  • Gauge Housings available in Aluminum, Brass, 316/316L Stainless Steel and Acetal Plastic
  • Wide Range of Elastomers

Special Features:

  • Over-range Protection Full to Maximum Working Pressure
  • Panel Mounting Standard, Front or Rear Panel
  • Pipe Mounting Kit Optional – 2″ U-Bolt
  • Wall Mounting Optional – Rear Mount
  • NACE Compliance Optional

Model 146 Differential Pressure Indicator / Switch

Product Features:

    • Differential Pressure Range 0-50″ H2O (0-125 mbar) to 0-30 PSID (0-2.0 bar)
    • Accuracy ±5% F.S.
    • Dial Size
      • Single 1-1/4″ x 2-1/4″ Oval (Std.)
      • Dual 1-1/4″ x 2-1/4″ Oval (Opt.)
    • Working Pressure 1,000 PSIG (70 bar)
    • Operating Temp. -40º F To +200º F (-40ºC to +93ºC)
    • Body Material – Aluminum, Brass, 316/316L
    • Internal Materials – 316 Stainless Steel
    • Elastomers Buna-N (Std), Viton®* , Neoprene, Ethylene-Propylene, Silicone
    • Switch Option
      • SPDT 3W, 125 VAC/VDC, 0.25 Amp
      • SPST 60W, 240 VAC/VDC, 3 Amp
    • Switch Mounting Pre-set in Tube, Flat Pack, Din Connector
    • Process Connections
      • 1/8″ FNPT Back Conn. (Opt.)
      • 1/8″ FNPT Bottom Conn. (Std.)
    • Dimensions 1.7H” x 2.5W” x 2.9L”
    • Weight 2.5#

    * Viton® is a Registered Trademark of DuPont Dow Elastomers

Common Applications

    • Filter Monitoring
    • Strainer Monitoring
    • Water System Applications
    • Refrigerant Filtration Systems

Model 522

Product Features:

  • DP Ranges from 0-5 PSD to 0-50 PSID
  • Elastomer Diaphragm Sensing Element
  • Up to 1000 PSIG Working Pressure (69 bar)
  • Maximum DP Pressure: (High to Low) 200 PSID
  • Gauge Housings available in Aluminum, 316/316L Stainless Steel and Acetal Plastic
  • Buna-N and Viton Elastomers

Special Features:

  • Standard: Panel Mounting, Front or Rear Panel
  • Optional: (2) 10-32 Mounting Holes on back of gauge body – 1.75″ Apart x .330″ Depth

Model 522 – Colour

Product Features:

  • 3-Color, Green Clean/Yellow Change/Red Dirty
  • DP Ranges from 0-5 PSD to 0-50 PSID
  • Elastomer Diaphragm Sensing Element
  • Up to 1000 PSIG Working Pressure (69 bar)
  • Gauge Housings available in Aluminum, 316/316L Stainless Steel and Acetal Plastic
  • Buna-N and Viton Elastomers

Special Features:

Standard: Panel Mounting, Front or Rear Panel, (2) 10-32 Mounting Holes on back of gauge body – 1.75″ Apart x .330″ Depth

Models 700, 710, 715

Product Features:

  • Available Ranges:
    0-5 PSID (0.35 bar) to 0-300 PSID (0-20.0 bar)
  • Use with Liquid or Gas media compatible with material of construction
  • Full stainless steel construction, compact size, easy installation
  • Laser welded, fully-sealed construction: NEMA 4X (IP65)
  • Utilizes Piezoresistive Differential Pressure Sensor Isolated Diaphragm
  • Zero Adjust / Potentiometer ±5%
  • Span Adjustable / Potentiometer ±5%
  • CE Certified to EMI / EMC Directive
  • LCD or LED display available upon request
  • Maximum Overpressure:
    (+) Hi-Side equals 2 times specified DP range
  • Maximum Overpressure:
    (-) Low-Side is equal to specified DP range
  • Maximum Static Pressure 2,900 PSI
  • Operating temperature limits – 14° F to 175° F.
  • Storage temperature is -40° F to 200° F
  • Sensor is temperature compensated from 32° F to 122° F
  • Model 700 is Manufactured in China

Mid-West Instrument Model 700 Wet/Wet Differential Pressure Transmitter utilises a piezoresistive differential pressure sensor sensing element with stainless steel isolated diaphragm. Silicon oil is filled in between die and two diaphragms. The measured differential pressure is transmitted onto the die through the diaphragm and silicon oil. The signal output generated by the piezoresistive bridge sensor is amplified into a useable voltage or 4-20 mA output as specified by customer. 1 Year Limited Warranty from Mid-West Instrument.